Mental rotation is the process of mentally revolving 3d and 2d figures (or letters) into different spatial orientations and often associated with the judging of ones spacial processing ability as well as a persons level of intelligence. Mental rotation ability is measured by testing the speed and accuracy in which one is able to decipher between which pairs of shapes have been revolved about a central point, and pairs of shapes which are mirrored versions of the initial figure. In 1971, Roger Shepard and Jacqueline Metzler introduced the concept of mental rotation to the field of Cognitive Psychology after performing a series of studies measuring the reaction time and degree of accuracy in which it took participants to recognize whether between a pair of figures, the second shape was identical to the first and had simply been rotated about a point or was a reflected/mirrored version of the original figure. It is my belief that both the reaction time and percentage correct are greatly affected by angular disparity and are negatively correlated as a function of angle. I predict that the highest reaction time and lowest percent of accurate shape identifications will occur when a shape has been mirrored and rotated more than 90 degrees from it’s initial starting point. I believe that there will be both lower reaction time and a higher percent correct when blocks are rotated to a position that has a lower degree of angular disparity when juxtiposed with the original arangement of blocks. According to an article titled Mental Rotation by Yohtaro Takano in The Encyclopedia of Cognitive Science, “When angular disparity exceeded 180 degrees, it was found that response time did not continue to increase monotonically but turned to decrease up to 360 degrees. In other words, it showed non-monotonicity at 180 degrees.” In other words, studies have shown that response time in relation to a shape being rotated 360 degrees would take on the shape of an inverted V or U when graphed with response time being a function of the degrees blocks were rotated. I believe that mirrored and non-mirrored will have a similar reaction time as the same number of degrees will need to be mentally rotated in order to confirm or refute which pairs match and which shapes are reflected versions of the original. In the same article mentioned earlier by Yohataro Takano, farmiliarity was found to be a major factor in the speed of mental rotation, “When two objects are not mirror images of each other, there always exist structural differences that are orientation-free. Imagine, for example, that a non-mirror-image ‘different’ object is made by adding one more cube to the end of the left object’s ‘arm’. Then, it will be easy to tell whether a test object is the same or different, irre- spective of its orientation. Mental rotation is not needed in this case.” Since the pairs of shapes in the online experiment were either mirrored or rotated from the original figure, it is my belief that as the 6 shapes started to repeat in the test pattern, reaction time will show a decrease. However, I believe that the decreased reaction time will have a negative effect on the percent of pairs correctly identified as matching. As participants become more and more comfortable with the simplicity and patterns of angular disparity, I believe that students will have taken less time to mentally rotate an object fully back to its previous position and rather fail to identify when objects are in fact unaligned versions of one another.

In the online class experiment, 57 undergraduate college students were tested in both speed and accuracy when identifying whether shapes could be rotated about a fixed point to align with the foundational figure, or if the blocks had been reflected and transformed to mirror the primary block shape. There were six different patterns that the blocks were shaped into that repeated throughout the experiment. The six shapes were either rotated in increments of 45º (0º, 45º, 90º, 135º, 180º, 225º, or 270º), reflected across a vertical or horozintal axis, or some combination of the two. During the experiment, participants were presented an online examination where two shapes were separated into the right and left quadrants of the screen. The figure on the left represented the pre-altered figure whereas the figure on the right had been modified by degree of rotation reflected to create a mirrored version of the initial block shape. Participants in the experiment were instructed to decide if the figure was rotated or reflected, then instructed to select a a letter on the keyboard which was chosen to represent one of the two options. Once the student struck a key, a different pair of bocks would again appear on respective sides of the screen and the process would be repeated. The amount of time it took for each student to decide how the blocks had been altered were recorded along with the degree to which it had been rotated, if the figure was mirrored or not-mirrored, and also the what percent of the class had accurately judged the path of alteration for each of the six shapes. Two different versions of the data were then charted in excel: the first was the reaction time for each block at various degrees (mirrored and not-mirrored) and the other set of data was the percentage of alterations which were correctly identified for each block at each of the seven various degree rotations (mirrored and not-mirrored).